Art of forming composite metal structures.



No. 655,457. Patented Aug. 7, I900. W. H. SAVERY.

ART OF FORMINGCOMPOSITE ME TAL STRUCTURES.

(Application filed Nov. 17, 1899.)

(No Model.)

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UNITED STATES PATENT Orrrcn.

WILLIAM H. SAVERY, OF WILMINGTON, DELAIVARE.

ART OF FORMING COMPOSITE METAL STRUCTURES.

SPECIFIUATION forming part of Letters Patent No. 655,457, dated August '7', 1900.

Application filed November 17, 1899. Serial No. 737,360. (No model.)

To all whom it may concern.-

Be it known that 1, WILLIAM H. SAVERY, a citizen of the United States, residing at Wilmington, county of New Castle, and State of Delaware, have invented certain new and useful Improvements in the Art of Forming Oomposite Metal Structures, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to certain improvements in the art of forming composite metal structures, the component parts of which consist, in whole or in part, of steel castings and wrought-steel or wroughtiron. I

Ordinarily in the manufacture of metal structures which consist of steel castings and wrought-steel or wrought-iron what may be termed the plain or simple parts of the structure are formed from the rolled metal, and those parts of the structure which are complex or of peculiar configuration are formed from cast-steel. Thus, for instance, in the manufacture of boilers or other similar large metal structures consisting of a body portion and heads the body portion is formed from a rolled-metal plate or plates. The heads, trunnions, or tracks, however, are usu ally formed from steel castings, these castings being united to the other parts by rivets. Similarly in the making of metal pipe having flanged or bell-shaped ends the body portion of the pipe is formed from a steel or Wroughtiron plate or plates, and the flanged ends are usually formed from steel castings,the flanged or bell-shaped ends being riveted to the body portion. Structures formed in this way are objectionable, because the riveting necessarily weakens the metal, so that the joint thus formed has not the strength of the adjacent parts of the structure, and also because of the difficulty in forming tight joints. Furthermore, in case the structure is to be used for containing or conveying substances containing certain chemicals the joint between the rivet and the material through which it passes will be attacked by the chemicals, and leakage results' In smaller structures it is possible to avoid these objections by casting the entire structure. This, however, is objectionable on account of the expense and is practically impossible in the case of large structures-such, for instance, as digesters. I have discovered that it is possible to form what may be termed the simple parts of such composite structures from wrought-steel or wrought-iron and the other parts from castings, these component parts being united by welding. For instance, in making a digester or a boiler or a pipe the body portion can be made from rolled-steel plates or wrought-iron and the other partssuch as the heads, flanges, trunnions, or tracksfrom castings, the other parts bei ng united by welding.

In carrying the invention into effect I select metal for the castings and for the wrought body portions which is substantially the same in its characteristics. For instance, if I intend to form a pipe having a body portion made from rolled steel and having flanged ends OQ asQsEQI I use metal for the two parts which has substantially the same amounts of carbon, phosphorus, silica, sulfur, and the other constituent elements of steel. I have found that when steel castings and wroughtsteel or wrought-iron have substantially the same characteristics they can be welded without difficulty. Having, therefore, prepared a casting and rolled plates of steel or wroughtiron so that their characteristics are substantially similar, I proceed to heat and weld them in the ordinary manner. I have found by experiment that excellent results are produced by using steel castings and steel plates having substantially the following characteristics.

Physical properties: tensile strain, fiftyfive thousand to sixty thousand pounds per square inch; elongation in eight inches, twenty-five per cent. reduction of area, fifty per cent.

Chemical properties: carbon, (combined,) not over 0.18 per cent. phosphorus, not over 0.03 per cent; sulfur, not over 0.03 per cent.

While, however, steel having the properties above mentioned has proved suitable for carrying the invention into effect, it is to be understood that I do not limit myself to the use of steel having precisely these characteristics, since they may be varied considerably and still excellent results be produced.

The accompanying drawing illustrates in vertical section a composite metal structure formed in accordance with the invention.

, Referring to the drawing, 1 indicates the body portion of aboiler or other similar metalcontaining vessel. This body portion is formed in the present instance of rolledsteel plate. The heads or ends 2 3 of the boiler are formed of cast-steel.v The head 2 is shown as welded to the body portion, and the head 3 is shown as separate therefrom, but will be welded to the body portion, as is the head 2, when the boiler is complete. 4 indicates a casting surrounding an orifice to which the steam-outlet pipe may be connected, said casting being also shown as welded to the body of the boiler.

It is to be understood that. the cast-steel heads 2 and 3 and the casting 4 are composed of steel, which has substantially the same characteristics as the rolled-steel plate of the body portion 1.

It is to be further understood that the invention is not confined to any particular form of metal structure, as it is applicable to any composite structure, a part or parts of which are to be formed of rolled or Wrought steel and another part orparts of which are to be formed from cast-steel.

What I claim is- 1. The improvement in the art of forming a composite structure from a steel cast-ing or castings and wrought-steel or wrought-iron which consists in forming the casting or castings and the wrought-steel or wrought-iron from metal having substantially the same characteristics and uniting them by welding, substantially as described.

2. The improvement in the art of forming a composite structure from a steel casting or castings and wrought-steel or wrought-iron which consists in forming the plain or simple parts of the structure from wrought-steel or wrought iron, forming other parts of the structure from a steel casting or castings having substantially the same characteristics as the wrought-steel or wrought-iron, and uniting the casting or castings and wrought-steel or wrought-iron by welding, substantially as described.

3. The improvement in the art of weldingteristics, and uniting by welding, substan- V tially as described.

4. The improvement in the art of welding steel castings and wrought-steel or wroughtiron which consists in preparing a casting I from metal which has substantially the same characteristics as the wrought steel or wrought-iron, and uniting by welding, substantially as described.

5. The improvement in the art of welding steel castings and wrought-steel or wroughtiron which consists in preparing one of the parts of the welded structure from metal which has substantially the same characteristics as the other part and uniting the two by welding, substantially as described.

6. A metal structure consisting in part of wrought-steel or wrought-iron and in part of cast-steel having the same properties as the wrought-steel or wrought-iron, the said parts being united by welding, substantially as de scribed.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

VILLIAM H. SAV ERY.

Witnesses:

THos. I-I. SAVERY, J r., HOWELL S. ENGLAND. 

